I Built BreakFinder: Personalized Surf Forecasts + Full Garmin Ecosystem

I Built BreakFinder: Personalized Surf Forecasts + Full Garmin Integration

I try to build something surfers actually needed.

Today I'm sharing the technical journey, what worked, and what I'd do differently.

The Problem:

I'm a surfer. I check forecasts constantly. But here's the thing:

A 6ft beach break ≠ a 6ft reef break

Most forecast apps show you swell size and wind direction. Cool. But they

don't tell you if the break matches YOUR skill level.

Or if you're about to paddle into something dangerous.

So I spent 2 months building BreakFinder to solve that.

The Solution: Three Pillars

Personalized Condition Scores

Instead of generic forecasts, BreakFinder gives you a personalized condition

score based on:

• Your preferred wave height range


• Your preferred wind direction


• Your preferred tide


• Your preferred wave period

Example:

• Forecast: "6ft swell, 15kt offshore wind"


• My app: "🟢 Perfect for you today" (because I'm intermediate + like 4-6ft)


• But for a beginner: "🔴 Too big for your level"

Full Garmin Integration (100+ Devices)

This was the hardest part. I integrated with Garmin because I use a Garmin

watch and wanted accurate session tracking.

What's included:

• 5 Connect IQ apps (Forecast, Session Tracker, Surf Skate Tracker, Watch Face,
  Breath Training)


• Wave counting (how many waves you caught today)


• Post-session data sync to your account at BreakFinder

Why it was hard:

Garmin's Connect IQ SDK is powerful but poorly documented. I had to:

• Support 100+ different watch models (each with different capabilities)


• Handle offline functionality (watches have limited storage)


• Optimize for battery life (can't drain your watch)


• Build fallbacks when devices don't support certain features

Worth it? Maybe.

Skill-Level Spot Matching

The database of 1500+ spots includes difficulty ratings. So when you're trip

planning, you see:

• Beginner spots: Mellow beach breaks


• Intermediate: Reefs with some risk


• Advanced: Heavy breaks (Sunset, Pipe territory)

The Tech Stack

Fullstack:

• Rails 7 (API + Monolith)


• Hotwire (Turbo + Stimulus)


• PostgreSQL for user data + spots


• Redis for caching forecasts


• Event-Driven-Architecture

External:

• Garmin Connect IQ SDK (C++)


• OpenMeteo for first 7 days forecast data


• NOAA for 8–16 days forecast data (own blog worth documenting the pain)


• Geocoder (Ruby Gem)


• Leaflet for spot maps

DevOps:

• Docker for dev environment


• Hetzner + Kamal (loving it! So easy and cheap)


• GitHub Actions for CI/CD

Current Metrics (2 Months In)

• 
  5,000 downloads (Garmin IQ Store)


• 
  3.9★ rating (honest reviews, we support 100+ devices = some quirks and early version had some major issues like no wave counting at all)


• 1000+ registered surfers

What's Next

Business Side (Launching Feb 2026)

Here's where it gets interesting. I'm building a marketplace for local

guide operators.

The idea:

• Small surf shops, guides, crews can list themselves


• Traveling surfers can find them directly


• Fair pricing (€19-€299/month per business, NO algorithm trap)


• No 30% commission like booking platforms

This is where the real revenue lives. A solo surfer might pay €5/month.

A local business? They'll pay €50-200/month to reach customers.

For Other Solo Devs

If you're building something:

1. 
   Pick a niche you understand deeply (I am a surf addict)


2. 
   Focus on one metric early (mine: Garmin support)


3. 
   Write about the technical journey (not just the marketing angle)

Links

Questions?

I read every comment. Ask me about:

• Garmin APIs


• Rails architecture


• Forecasting algorithms


• What I'd do differently


• Building as a solo dev

Let's talk! 🏄‍♂️